This document summarizes the conclusion of an ekoSign project. It describes the testing and experimental results, including unit, integration, and system tests. It also documents the application programming interface, including classes for encryption, decryption, digital signatures, and signature verification. Finally, it discusses lessons learned, including how digital signatures can enable new business processes and the benefits of using XML for multiple document ownership.

1. SENIOR PROJECT 2007-2008
(Conclusion of the ekoSign project)
9. Conclusion
Experiences Gained and Conclusions
After the Project
Project team members
Hüseyin Çakır, Mehmet Mesut Özışık, Yılmaz Kaya
Abstract:This paper gives some brief information about the last phase of the project. It consists of four
main parts which are; Testing/Experimental Result, API Documentation and Experiences/Lessons learned.
Keywords:Testing/Experimental Result, API Documentation and Experiences/Lessons learned.
http://groups.google.com/group/digitalsignature
digitalsignature@googlegroups.com
PRINT DATE: 05/06/08
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2. 9.1 Introduction
This paper belongs to the transition phase of the unified process and it mainly represents the work
done at last step of the project. Figure 9.1 shows the steps of the unified process and which step the
introduction paper belongs to.
Inception
Elaboration
1.Introduction
2.Project Plan
3.Basic Concepts
4.Scenario
Construction
5.CSorder
6.SDSorderW
7.SDSorderM
8.MSorderW
Transition
9.Conclusion
Figure 9.1 Steps of Unified Process.
9.2 Testing/ Experimental Result
We tried to conduct a series of different tests to fully exercise the system. The tests we use are;
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Unit Test,
Integration Test,
9.2.1 Unit Test
In unit test we test an unit (class) of the whole working system. We tried to identify unit-level
defects by causing corresponding failures to occur and also determine if the unit is complete and
ready to be submitted for integration as part of a code build.
9.2.2 Integration Test
In integration test, the units (classes) are test in order to be sure that they can work in agreement
with each other without causing any serious mistakes. We tried to identify cause of failures
involving the distribution of integrated system components and be sure about units (classes) can be
fully integrated to satisfy requirements.
9.2.3 System Test
In system test, the whole system is tested and verified that it met the requirements defined in the
introduction document. We tried to conduct functional, performance and security tests during the
system test. We made it sure that user interface standards, and screen look maintain consistency
with the rest of the application. We also tried to check for valid, invalid and limit data input.(e.g.
invalid e-mail input). As a testing phase we needed experienced testers on this project to develop,
perform and validate tests. Since we are not familiar with the testing tools. Unexpected turnovers
can impact the system.
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3. 9.3 API Documentation
In this project, we used Visual Studio 2005 and as a programming language we used C#, ASP.NET
and XML. We also tried to use class hierarchy and object oriented programming structures to make
our application easier to maintain and use modern software developing standards.
We have six main classes in the project. The classes that provide encryption, decryption, XML
signatures and verifying XML signatures are;
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encryption class,
decryption class,
signature class and
verifySignature class.
9.3.1 Encryption Class
“encryption” class has a method “Encrypt” that encrypts an XML element using two keys. It
generates a cryptographic public/private key pair and saves the key pair to a secure key container.
The method then creates a separate session key using a cryptographic algorithm. The method uses
the session key to encrypt the XML document and then uses the public key to encrypt the session
key. Finally, the method saves the encrypted session key and the encrypted XML data to the XML
document within a new <EncryptedData> element. The codes about “encryption.cs” are in
Appendix.
9.3.2 Decryption Class
“decryption” class has a method “Decrypt” that decrypts an XML element that had been encrpted
before in other words “Decrypt” method can only decrypt documents that present the specified key
name. The codes about “decryption.cs” are in Appendix.
9.3.3 Signature Class
“signature” class includes a method “SignXml” that sign XML document and attach the signature
to the document in a <Signature> element. The method creates an cryptographic signing key, adds
the key to a secure key container, and then uses the key to digitally sign an XML document. The
key can then be retrieved to verify the XML digital signature, or be used to sign another XML
document. The codes about “signature.cs” are in Appendix.
9.3.4 verifySignature Class
“verifySignature” class includes a method “VerifyXml” that verifies whether the document was sent
from the authorized entity or not. And from the structure of the XML verifying signature also
checks the integrity of the XML document so if any unauthorized change occur in XML document,
it is not going to be verified by this method. It also provides multiple signatures in XML by the use
of reference element in the XML. The codes about “verifySignature.cs” are in Appendix.
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4. 9.4 Experiences/ Lessons Learned
The digital signing process is used to replace traditional document signing by companies. A lot of
companies use paperwork systems that have not been computerized because they are based on
documents rather than data records. Also a lot of tools used by organizations does not allow
multiple document ownership so they don't fit into existing work flow structure of the companies.
As Gupta mentioned Digital signatures have natural applications in many business processes. This
technology can move beyond playing the role of supporting organizational processes to actually
enabling business processes. However, a different paradigm needs to be established. In particular,
documents have to be explicitly managed as a collection of entities that can have multiple
ownerships[1]. In addition to that the usage of XML provides a powerful structure that eases the
multiple ownership encryption and digital signature on digital documents.
During this project we learned the standard XML structure and how it is used in encryption and
digital signing. We also learned that C# can easily be used for XML document signing and
encryption. We gained the knowledge of using unified process with IEEE software engineering
standards. We developed the project by using Microsoft industry standard for achieving the goal of
a secure and authentication-based automated document management.
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5. 9.5 References
[1]. A. Gupta., Y.A. Tung, J.R. Marsten, “Digital signature: use and modification to achieve success
in next generational e-business processes”, Science Direct, p.571, June 2003. [Online]. Available:
http://www.sciencedirect.com. [Accessed May 06, 2008].
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